JPS62181376A - Polyurethane adhesive composition - Google Patents

Abstract

PURPOSE:The titled composition, containing two kinds of high-polymer polyols containing a specific structural units and organic polyisocyanate at a specific ratio, having improved adhesive force and heat and hot water resistance and suitable for bonding plastic, metal, rubber, etc. CONSTITUTION:A composition containing (A) a polyester polyol having 3,000-50,000 number-average molecular weight or (B) a high-polymer polyol, consisting of a polyester polyurethane polyol consisting of (i) a polyester polyol having 600-8,000 number-average molecular weight and (ii) an organic diisocyanate and having 3,000-50,000 number-average molecular weight and the components (i) and (ii) containing diol residues expressed by formula I in the molecule and dicarboxylic acid residues being expressed by formula II (n is 1-12) and formula III (Ar is 6-10C bifunctional aromatic group) at 1/5-5/1mol ratio of the residues expressed by formula II to the residues expressed by formula III and (C) an organic polyisocyanate at 1-10 equivalent ratio (NCO/OH).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a novel polyurethane adhesive composition that has excellent adhesive strength, heat resistance, and hot water resistance, and is particularly useful as an adhesive for glass, metal, rubber, fiber, etc. The present invention relates to a polyurethane adhesive composition.

Conventional technology In recent years, for example, polyethylene, polypropylene, polyamide (nylon, polyester,
Two or three or more layers of ethylene-vinyl acetate copolymer or its saponified product, plastic films such as vinyl chloride and cellophane, and metal foils such as aluminum foil have been developed and used for various purposes.

Dry lamination is the method of lamination.

Methods such as wet lamination, hot melt lamination, and extrusion lamination are known.

In particular, with the recent improvement in dietary habits, laminated films,
The variety of foods packed using so-called laminate films has increased, and for this reason, lamination processing of various films has become important. Along with this, there are many different types of adhesives used in the production of laminated products.
In addition, higher performance is required. For example, it adheres well to various adherends, has wide applicability, and has excellent adhesive strength, hot water resistance,
Improvements in flexibility, heat resistance, drying properties, and other processability are strongly desired.

In particular, adhesives for packaging laminated films used in retort pouch foods, which have shown remarkable growth in this field in recent years, and food products that require boiling and more, have extremely excellent normal adhesive strength, initial adhesive strength, Hot water resistance, content resistance, and flexibility are required. Furthermore, in order to meet these requirements and be used as an adhesive in general laminated film fields such as snack foods, it must have good wetting properties for all adherends used there.
It is important to have hydrolysis resistance, light resistance, transparency, and high speed lamination properties. Polyurethane adhesives are widely used as adhesives that can meet these demands to some extent.

Problems to be Solved by the Invention However, when conventional polyurethane adhesives attempt to satisfy the above-mentioned wettability and flexibility, a phenomenon occurs in which the other performances described above deteriorate.

For example, poor wetting properties may cause the adhesive to repel or cause partial adhesion failure after being applied to the film.

In addition, if the flexibility is not sufficient, when the adhered film is peeled off, in the case of some types of adherends, it may suddenly peel off with a "burin" sensation. Furthermore, the same applies to low-temperature flexibility, that is, the above-mentioned properties at low temperatures. in this way,
All of the above performance requirements were not met. For this reason, the number of polyurethane adhesives used in laminated products is extremely large, making it extremely inefficient and uneconomical when manufacturing a wide variety of laminated products. This clearly shows that there is still no high-performance polyurethane adhesive with wide applicability.

In view of the above facts, the present inventors have determined that the product has good wetting properties for all adherends, as well as excellent adhesive strength in normal state, initial adhesive strength, hot water resistance, transparency, hydrolysis resistance, and flexibility. Extensive research has been carried out with the aim of providing a versatile, high-performance polyurethane adhesive composition with extremely good performance and wide applicability. Note that having excellent flexibility does not mean that when the adhesive film is peeled off, it will peel off with a "crisp" feeling, but that the flexible polyurethane adhesive will "wrinkle" on any adherend. It means something that feels like it's peeling off.

Means for Solving the Problems According to the present invention, the above object is achieved by using a polymeric polyol (4).
and the organic polyisocyanate (B) at an equivalent ratio of isocyanate groups to hydroxyl groups (NCO/OH) of 1 to 10H.
) In the adhesive composition formed by containing the polymer polyol in a ratio of j to 10, the polymer polyol has a number average molecule flf 5+
OOC1~so,ooo polyester polyol (A
1) or a polyester polyurethane polyol (A2) with a number average molecular weight of 3,000 to so, o o o made from a polyester polyol with a number average molecular weight of 600 to a, o o o and an organic diisocyanate, and the number average molecular weight is A polyester polyol having a molecular weight of 3,000 to so, ooo and a polyester polyol having a number average molecular weight of 600 to 8,000 contain a structural unit represented by the formula % (1) as a diol-based unit in the molecule, and As a unit based on dicarboxylic acid, a structural unit represented by the formula (in the formula, n represents an integer of 1 to 12) and (in the formula, Ar is a divalent aromatic hydrocarbon residue having 6 to 10 carbon atoms) Achieved by a polyurethane adhesive composition characterized by containing a structural unit (representing a group) in a molar ratio of structural unit [1]/structural unit [1] of 115 to 5/1. be done.

The present invention is an adhesive containing a polymeric polyol (4) as a main ingredient and an organic polyisocyanate (B)' as a curing agent, and the adhesive is useful as an organic solution type two-component curing adhesive. .

The polymer polyol (A) used as the main ingredient in the present invention has a diol-based unit in the molecule with the formula (+
) containing the structural unit [1] represented by the formula (1) and the structural unit represented by the formula (1.m) as a unit based on dicarboxylic acid. ]/115 to 5 in molar ratio of structural unit C1,l
polyester polyol containing the polyester polyol at a ratio of 1/1, and a polyester polyurethane polyol containing the polyol as a glycol component.

Polyester polyol (A1) and polyester polyurethane CH2 related to the above polymer polyol (4)
The structural unit (1') of -CH2-0-(I) can be produced by the above formula (1
) may be partially replaced with other diol residues. Depending on the structure of the adhesive or the type of adherend, good results may be obtained when other diols are used in combination.

Substitutable diols include ethylene glycol, j,
4-7”tanediol, 1,6-hexanediol, 1
．． 9-nonanediol, diethylene f 17 col,
Diols having 2 to 12 carbon atoms such as neopentyl glycol can be mentioned. It is also perfectly acceptable to use a small amount of a polyhydric alcohol such as trimethylolpropane, glycerin, or pentaerythritol in addition to the above diol. In any case, it is desirable that the structural unit [1] accounts for 20 moles or more of the diol component, preferably 30 moles or more, more preferably 50 moles or more, and most preferably 80% or more.

On the other hand, the structural unit based on dicarboxylic acid has the formula %formula%(1
) and the formula -C-Ar-C(■). In the formula (1), n represents an integer of 1 to 12, and examples of aliphatic dicarboxylic acids that produce the formula (seal) include succinic acid, glutaric acid, adipic acid, azelaic acid, cepatic acid, Examples include dodecanedioic acid.

More preferably adipic acid.

These are azelaic acid and sepathic acid. These dicarboxylic acids may be used not only alone but also in combination of two or more. Furthermore, in the above formula (1), Ar is a divalent aromatic hydrocarbon residue having 6 to 10 carbon atoms, and the residue is a phenylene group or a naphthylene group, and the above formula (1)
Specific examples of aromatic dicarboxylic acids that can produce terephthalic acid, isophthalic acid, orthophthalic acid,
Examples include naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and mixtures thereof in arbitrary proportions. More preferred are terephthalic acid and isophthalic acid. Further, as the above-mentioned aromatic dicarboxylic acid, an alkyl ester thereof can also be used.

In the polyester polyol, structural unit (1)
/ (total of structural unit [I] and structural unit [bacteria])
The molar ratio is good as long as it is such that the molecular terminal of the produced polyester polyol becomes a hydroxyl group. On the other hand, the structural unit [seal] and (#f structural unit l in 1, 1)
/ structural unit [m] varies depending on the use of the adhesive, but it is generally important that it is within the range of 115 to 5/1, more preferably 1/4 to 4/1, but When used as a companion adhesive for laminating food packaging materials, Vi1/3 to 3/1, optimally 1/2 to 2/
It is desirable that it be in 1.

When the molar ratio is 5/1 or more, initial adhesive strength, heat resistance, hot water resistance, and normal adhesive strength are poor. If it is less than 115, it is not preferable because the wetting properties for various broken adherends, flexibility, and low-temperature flexibility are insufficient.

There is no immediate restriction on the method for producing the polyester polyol, and known polyester condensation polymerization means can be applied. For example, the above compounds capable of producing structural units (1), (1) and [O] are charged in a desired ratio, and 150
~25 Esterification or transesterification with Q'C,
It can be produced by further condensing and polycondensing the reaction product obtained in the above manner under high vacuum at 200 to 500''C.

In this case, although it is possible to simultaneously charge all three components and prepare all of the copolymerized polyester polyols as described above, the following method may also be adopted.

That is, a polyester polyol containing (1゛qq monomer 1) and [II'] and structural units (1) and [
A polyester polyol containing a polyester polyol containing a polyurethane is synthesized separately and used by completely mixing the two so that the molar ratio of the structural unit [a]/structural unit [1] satisfies a range of 115 to 5/1. It is also possible to do so.

In the present invention, the polymer polyol (A) is a polyester polyurethane polyol (A2) made from a polyester polyol (Ao) and an organic diisocyanate.
) is used.

The polyester polyol (Ao) has a molecular weight of 600 to 5.
000, preferably 1,000 to 2,500, more preferably 1,500 to 2,200. If the number average molecular weight is too small, problems arise in terms of wetting properties when the resulting polyester polyurethane polyol is used as an adhesive. On the other hand, if it is too large, the normal adhesive strength, especially the adhesive strength to aluminum foil, will be poor.

The organic diisocyanate used here includes known aliphatic, alicyclic, and aromatic organic polyisocyanates containing two isocyanate groups in the molecule, but especially 4.4' -di7-diylmethane diisocyanate, p-phenyl diisocyanate, toluylene diisocyphate, 1°5-7-tylene diisocyanate,
Examples include xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate. Among these, diisocyanates having isocyanate groups having different reactivity are preferred. Particularly preferred is isophorone diisocyanate, ld2,4-)lylene diisocyanate, or a mixture containing these as main components.

In addition to the above-mentioned organic dicyanate, a small amount of a polyfunctional polyisocyanate such as trimethylolpropane or triisocyanate prepared by adding 3 moles of tolylene diisocyanate to 1 mole of glycerin can be used.

At this time, a suitable chain extender may be used if desired, and the chain extender may be a chain extender commonly used in the polyurethane industry, that is, a compound containing at least two hydrogen atoms capable of reacting with incyanate. is included. Examples include ethylene glycol% 1.4-7
'Tandiol, 1゜6-hexanediol, xylyle/glycol, 3-methyl-1,5-hentanediol, bishydroxyethoxybenzene, neobentiruq'
J: + -l, 1,9-nonanediol, inphorondiamine, hydrazine, dihydrazide, trinotyolpropane, glycerin and the like.

Regarding the specific operation method for obtaining the polyester polyurethane polyol (A2)'x, a known urethanization reaction technique is used. For example, number average molecular weight 6
00 to 8,000 polyester polyol and optionally a low molecular weight compound having active hydrogen are mixed to form a polyester polyol of about 40 to 8,000
After preheating to 100 °C, the ratio of isocyanate groups to the number of active hydrogen atoms of these compounds (NGOloH)
It is obtained by adding an amount of organic diisocyanate such that the ratio is 1 or less, and reacting at 50 to 120°C for several hours.

Further, the above reaction may be carried out in the presence of an organic solvent inert to isocyanate groups. If desired, conventional urethanization catalysts such as organotin compounds, tertiary amines, etc. may be used. If the manufacturing process is carried out in the presence of organic solvents, it is advantageous to determine the use of organic solvents such that the solids content of the final mixture is between about 10 and 90% by weight, preferably between 20 and 807 ff%.

The polyester polyol (A1) or polyester polyurethane polyol (A2) used as polyol (2) in the present invention preferably has a number average molecular weight of usually 3.000 to 50.000, preferably 5,000 to 30.000. If this molecular weight is too small.

Initial adhesive strength and normal adhesive strength when used as an adhesive.

The hot water resistance and chemical resistance are poor, and if it is too large, the viscosity becomes high and the IIM resistance becomes poor.

In the present invention, the polymer polyol (A) is preferably a polyester polyurethane polyol (A2) from the viewpoint of normal adhesive strength, initial adhesive strength, heat resistance, and hot water resistance. Among them, for example, it is used as an adhesive for laminating packaging materials for retort food.

A polyester polyurethane polyol made of a polyester polyol (AO) having a number average molecular weight j of 500 to 2,200 and an organic diisocyanate having two isocyanate groups having different reactivity is preferred.

When polyester polyurethane polyol (A2) is used as an adhesive, its adhesive performance largely depends on the structural unit (1) in the polyester polyol (AoJ).The preferred structural unit [carbonate] is primarily a sepatic acid residue. can be,
Next is adipic acid.

The polyester polyol (A1) and the polyester polyurethane polyol (A2) may be used in combination in any ratio.

The organic polyisocyanate used as a curing agent in the present invention is a compound having three or more isocyanate radicals in the molecule, such as tolylene diisocyanate or xylylene diisocyanate, in which all hydroxyl groups such as trimethylolpropane, glycerin, and pentaerythritol are removed. , compounds urethanized with hexamethylene diisocyanate and the like.

In the present invention, the blending ratio of the base resin and the curing agent is determined by the equivalent ratio (N
GOloH) preferably ranges from 1 to 10, particularly from 1 to 7. When the equivalent ratio is less than 1, heat resistance is poor, resulting in delamination during retort treatment and a decrease in adhesive strength after retort treatment.

If it exceeds 1.0, the adhesive strength will decrease and flexibility will be lost.
This is due to the stress concentration at the contact radius interface due to the increase in the hardness of the adhesive due to the increase in isocyanate.

The greatest feature of the polyurethane adhesive composition of the present invention is that it wets all adherends well, has good processing properties, and satisfies all of the requirements of initial adhesive strength, normal adhesive strength, flexibility, and hot water resistance. It is.

The polyurethane adhesive composition of the present invention is, for example, a polyolefin (polyethylene, polypropylene).

Polystyrene, ethylene-vinyl acetate copolymer or its saponified product, vinyl chloride resin, polyester (polyethylene terephthalate, polybutylene terephthalate),
Heat I3Tw of polyamide (nylon la, polyurethane, etc.)
i-type resin, phenol resin, melamine resin, synthetic resin such as urinary resin, natural rubber or synthetic rubber, aluminum,
Suitable for bonding metals such as copper and iron, fibers such as woven fabrics and non-woven fabrics, as well as wood, glass, ceramics, etc.5.
In particular, since it has the above-mentioned features, it can be applied to a wide range of applications, such as adhesion of packaging materials for foods and medicines, construction materials, electrical parts, automobile parts, lamination of laminations, and plastic films. In particular, 100-140°
High-temperature sterilization treatment using hot water (C) is required, and foods such as vinegar, salt, and salad oil must be stored in large quantities for a long period of time, so films such as polyester or polyamide - metal foils such as aluminum - It is most suitable as an adhesive for packaging materials for retort foods that require lamination of materials with poor adhesion such as polyolefin film or polyolefin film-polyamide film.

The polyurethane adhesive composition of the present invention is used in a two-part curable adhesive method. A typical method of adhesion using this composition is as follows.

For example, a method is employed in which the adhesive composition is applied to the surface of a film or metal foil using a dry laminator, the container is volatilized, the adhesive surfaces are brought together, and the composition is cured at room temperature or under heating. The coating gk (solid content) of the adhesive composition applied to the surface of a film or metal foil is about 1 to 101F.

EXAMPLES Next, the present invention will be explained in more detail with reference examples, examples, and comparative examples.

Reference Example 1 (Manufacture of polyester diol) A mixture of 3-methyl-1,5-bentanediol (105 g), dimethyl isophthalate (116 g), adipic acid (29 g) and tetraisoproboxy titanate (0,019) Esterification was performed at 160 to 220°C under a nitrogen stream. After distilling off a predetermined amount of water and methanol, the degree of vacuum was gradually increased using a vacuum pump to complete the reaction. In this way, a polyester diol (hereinafter sometimes referred to as main ingredient A) having a molecular weight of about 10.000 was obtained. 100 g of the obtained polyester diol was dissolved in 100 g of ethyl acetate to reduce the solid content to 5.
A solution of 0fii% was obtained.

Reference Examples 2 to 6 Polyester diols (
Base ingredients B to E) were obtained. Obtained polyester diol 1
00g was dissolved in 100ml of ethyl acetate to obtain a solution with a solid content of 50%. Table 1 shows the molecular weight of the obtained polyester diol.

Reference Example 7 (Manufacture of polyester polyurethane diol) Dimethyl iso-7 tallate, adipic acid, 5-methyl-1
, 5-bentanediol [molecule f2. ooo, dimethyl isophthalate/adipic acid = 1/1 (mole ratio), 12009, inphorone diisocyanate 18 g and dibutyltin dilaurate (
After reacting a mixed solution of 0.059 (catalyst) at 80° C. for 10 hours, it was cooled and dissolved in 218 g of ethyl acetate to obtain a 50% by weight solution of polyester polyurethane diol (base ingredient F).

Reference Examples 8 to 13 An ethyl acetate solution of polyester polyurethane diol (main ingredient G-J) was obtained in the same manner as in Reference Example 7 using the diol and dicarboxylic acid compositions and composition ratios shown in Table 1.

Ratio Reference Examples 1 to 2 Polyester diol (base material K) and polyester polyurethane diol (base material L) were obtained in the same manner as in Reference Examples 1 and 7 using the compositions and composition ratios shown in Table 1.

Below 5: White Examples 1 to 11 and Comparative Examples 1 to 2 3 equivalents of tolylene diisocyanate was added to trimethylolpropane based on 100 parts by weight of each main ingredient prepared in the above reference examples and comparative reference examples. (Manufactured by Nippon Polyurethane Co., Ltd., Coronate L1, abbreviated as Coronate L in Table 2)
Or a product obtained by adding 3 equivalents of hexamethylene diisocyanate to trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd., Coronate) (L, abbreviated as Coronate HL in Table 2). Add a certain amount of SfR and make a 20% solution with ethyl acetate. The adherends were a 12μ thick polyethylene terephthalate film (abbreviated as PET in Table 2) and a corona-treated 50μ thick unstretched polypropylene film (abbreviated as cPP in Table 2). ) using
To laminate them, apply the above adhesive bath solution to them in a dry laminator at a solid content of about 3.0 g/n/
After the solvent was evaporated, it was bonded together. At that time, the wetting properties of the adhesive solution were investigated. The obtained laminate film was cut into a @15n test piece, and a T-peel test was performed using a tensile tester at a tensile rate of 500*/min to measure the initial adhesive strength. In addition, test pieces were prepared from the laminate films obtained by curing at 50°C for 3 days after lamination, and the normal adhesive strength, hot water resistance, l1i1. The chemical resistance and flexibility were evaluated. The results are shown in Table 2.

QvJ adhesive bond T-type peeling test similar to adhesive strength! 'A was done.

Hot water resistance and chemical resistance test In the hot water resistance test, the test piece was placed in a 50 (IC) autoclave with water and treated at 120''C for 5 hours, followed by a T-peel test to examine the state of peeling and strength. For the chemical resistance test, the test piece was immersed in a 4% acetic acid aqueous solution at 25°C for 4 weeks, and then a peel test was performed.

0 Flexibility Flexibility was determined by the appearance of peeling in each of the above peel tests. The meanings of the marks in the table are as follows.

○: Peeling strength: Uniform strength is shown because the peeling is greatly wrinkled.

Δ Part 2 Officially, it is very strong, but there are some parts that can be easily peeled off.

×: Easy to peel off and strength is low.

01re characteristics (observation results) ○: Can be applied uniformly.

Δ: Partially repelled.

×: Hashiku.

Examples 12 to 22 and Comparative Examples 3 to 4 The above Examples 1 to 11 and Comparative Examples except that a 15-nil thick aluminum foil (abbreviated as AI in Table 2) was used instead of the unstretched polypropylene film. Laminated films were produced in the same manner as in Examples 1 and 2, and various performances were evaluated. The results are shown in Table 2.

, 1 page margin Reference Examples 14 to 24 Polyester diols having various molecular weights were synthesized in the same manner as in Reference Example 1 using the diol and dicarboxylic acid compositions and composition ratios shown in Table 5. A solution having a solid content of 50% was prepared by dissolving 100 g of the obtained polyester diol and 100 g of ethyl acetate. Table 3 shows the molecular weight of the obtained polyester diol. Using this polyester diol, the composition shown in Table 3 was further prepared in the same manner as in Reference Example 7 to obtain an ethyl acetate solution of polyester polyurethane diol (base material N-X).

Examples 25 to 35 6 equivalents of metaxylylene diisocyanate was added to trimethylolpropane based on 100 parts by weight of each main ingredient prepared in the above reference examples (Kenate p11ON manufactured by Takeda Pharmaceutical Co., Ltd., in Table 4). [abbreviated as Takenate D11ON], a product obtained by adding 6 equivalents of inphorone diisocyanate to trimethylolpropane (Takenate D14ON manufactured by Kurade Pharmaceutical Co., Ltd., abbreviated as Takenate D14ON in Table 4)' or Takenate D 1 f 1:1 mixture of ON and Takenate D14[)N (abbreviated as Takenate D11ON and Takenate 1)14ON in Table 4)
4 to 6 parts by weight was diluted with ethyl acetate to a 20% solution to prepare an adhesive solution. As adherends, a polyethylene terephthalate film with a thickness of 12μ (abbreviated as PET in Table 4), aluminum foil with a thickness of 9μ (abbreviated as AI in Table 4), and a corona-treated unstretched polypropylene film with a thickness of 50μ (abbreviated as CPP in Table 4), the above adhesive composition was first applied to a polyethylene terephthalate film using a dry laminator so that the solid content was about 5.09/d, and then the solvent ? After volatilization, the adhesive surface was aligned with the surface of the aluminum foil. Apply the same adhesive solution to the other side of the aluminum foil using a dry laminator to a solid content of approximately 5.097 d, evaporate the solvent, and then apply the adhesive solution to the adhesive surface. Matched to unstretched polypropylene film. At that time, the wetting properties of the adhesive solution were investigated. Using the obtained laminate film, adhesive performance etc. were investigated in the same manner as in Example 1 and S. The results are shown in Table 4.

As is clear from the examples, the adhesive composition of the present invention has extremely excellent adhesive properties (initial adhesion, normal adhesion, hot water resistance, and chemical resistance), and is resistant to various exposures. It also has good wetting properties and flexibility for the wearer.

Claims (6)

[Claims] (1) In an adhesive composition containing a polymer polyol (A) and an organic polyisocyanate (B) in an equivalent ratio of isocyanate groups to hydroxyl groups (NCO/OH) of 1 to 10, The molecular polyol is a polyester polyol with a number average molecular weight of 3,000 to 50,000 (
A_1) or a polyester polyurethane polyol (A_2) with a number average molecular weight of 3,000 to 50,000 made from a polyester polyol with a number average molecular weight of 600 to 8,000 and an organic diisocyanate, and the number average molecular weight of 3,000 to 50. ,000 polyester polyols and polyester polyols with number average molecular weights of 600 to 8,000 contain a structural unit [I] represented by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) as diol-based units in the molecule. And as units based on dicarboxylic acids, there are formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (II) (in the formula, n represents an integer from 1 to 12) structural unit [II] and ▲ mathematical formulas, chemical formulas , tables, etc. ▼(III) (In the formula, Ar represents a divalent aromatic hydrocarbon residue having 6 to 10 carbon atoms) The structural unit [III] is converted to the structural unit [II]/structural unit A polyurethane adhesive composition containing [III] in a molar ratio of 1/5 to 5/1. (2) The polymeric polyol (A) contains a structural unit [I] represented by the formula ▲mathematical formula, chemical formula, table, etc.▼(I) as a diol-based unit in the molecule, and is based on dicarboxylic acid. The units include the formula ▲Mathematical formula, chemical formula, table, etc.▼(II) (In the formula, n represents an integer from 1 to 12) Structural unit [II] and ▲Mathematical formula, chemical formula, table, etc.▼( III) The structural unit [III] represented by (in the formula, Ar represents a divalent aromatic hydrocarbon residue having 6 to 10 carbon atoms) is expressed by the molar ratio of structural unit [II]/structural unit [III]. A patent claim that is a polyester polyurethane polyol with a number average molecular weight of 6,000 to 40,000 made from a polyester polyol with a number average molecular weight of 1,500 to 2,200 and an organic diisocyanate contained in a ratio of 1/5 to 5/1 The adhesive composition according to item 1. (3) The adhesive composition according to claim 1 or 2, wherein the organic diisocyanate is a diisocyanate whose main component is isophorone diisocyanate or 2,4-tolylene diisocyanate. (4) The adhesive composition according to any one of claims 1 to 3, wherein the structural unit [II] is a sepatic acid residue or an adipic acid residue. (5) The adhesive composition according to any one of claims 1 to 4, wherein the structural unit [III] is a terephthalic acid residue or an isophthalic acid residue. (6) The molar ratio of structural unit [II]/structural unit [III] is 1
The adhesive composition according to any one of claims 1 to 5, which has an adhesive composition of /2 to 2/1.